Many different types or equipment exists for dispensing purified drinking or spring water from storage bottles. As is widely known, in such a water cooler apparatus, a water bottle is inverted and placed within a free-standing base unit. The base unit includes a holding tank and a valve spigot, or other delivery device which is operated to dispense the water as needed, typically via gravity.
While the water is originally delivered to the user in a clean and sealed bottle, a water cooler is typically located in an office, factory floor, or other environments which may contain unhealthy bacteria in the air or other ambient environmental conditions that may foster the growth of undesirable microorganisms. This, in turn, means that undesirable biological growth may occur in the holding tank, and as time elapses, this eventually contaminates the water as it is dispensed from the bottle.
Most users of bottled water dispensers do not clean the inside of the holding tank for various reasons. This may include ignorance of the fact that bacteria is growing therein, or, even if the user knows of the hazard, human nature being what it is, the time is not taken to perform the task. This is because gaining access to the holding tank of a standard water cooler may be difficult. As a result, this lack of cleaning leaves the holding tank in an unsanitary condition, and defeats the purpose of providing bottled water in a clean and sealed condition in the first place.
Certain persons have previously recognized the problem of bacteria formation within the holding tank of a free-standing water cooler system. For example, U.S. Pat. No. 4,322,291 issued to Ho, discloses a water dispenser consisting of a series of transparent concentric plates. The center section of the tank is provided with a transverse-mounted transparent protecting tube within which is located in ultra-violet (UV) lamp, which serves to sterilize the water. The apparatus shown in that patent thus requires the use of a special multi-section tank, which includes a series of concentric transparent plates. The vast majority of water cooler systems in use do not have such a holding tank, and therefore may not easily be retrofitted without undue cost.
What is needed is a way to retrofit existing water cooler systems whereby the stagnant water standing in the holding tank might be disinfected, such as by automatically exposing the tank to UV light, without the need to retrofit or redesign the holding tank itself.